John Grier Dam dam
John Grier Dam
Located in McCormick, South Carolina, the John Grier Dam is a privately owned structure with a primary purpose of irrigation. Built in 1910 and designed by the USDA NRCS, this earth dam spans 525 feet in length and stands at a height of 23 feet. It holds a normal storage capacity of 101 acre-feet and is situated on the TR-ROCKY CREEK, serving as a vital resource for agricultural water supply in the region.
Despite its importance, the John Grier Dam is currently in poor condition, with a low hazard potential. The last inspection in September 2017 highlighted the need for improvements to ensure its continued safety and functionality. The dam is regulated by the South Carolina Department of Health and Environmental Control, with state permitting, inspection, and enforcement in place to oversee its operation and maintenance.
With a moderate risk assessment rating, stakeholders and water resource enthusiasts are urged to monitor the John Grier Dam closely and advocate for necessary upgrades to enhance its resilience to climate change impacts. As a key infrastructure supporting irrigation and recreational activities, the dam plays a crucial role in the local community and underscores the importance of proactive dam safety measures in the face of evolving environmental challenges.
Dam data reference
Condition Assessment
- Satisfactory
- No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
- Fair
- No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
- Poor
- A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
- Unsatisfactory
- A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
- Not Rated
- The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Hazard Potential Classification
- High
- Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
- Significant
- Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
- Low
- Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
- Undetermined
- Dams for which a downstream hazard potential has not been designated or is not provided.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around John Grier Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Little River Near Mt. Carmel | 1,120 cfs | → |
| Stevens Creek Near Modoc | 585 cfs | → |
| Lake Greenwood Tailrace Nr Chappells | 4,240 cfs | → |
| Saluda River At Chappells | 4,110 cfs | → |
| Saluda River Near Ware Shoals | 1,590 cfs | → |
| Broad River Near Bell | 1,550 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near John Grier Dam.
Boat launches
- Highway 28, Mccormick
- State Road S-33-277, Mccormick
- Long Cane Creek Boat Ramps
- Baker Creek Ramp Drive Mccormick County
- Bakers Creek Boat Ramp
- Little River Boat Ramp
Campgrounds
- Morrow Bridge And Midway Seasonal Camps
- Baker Creek State Park
- Parsons Mountain Lake
- Hickory Knob State Resort Park
- Hawe Creek - Strom Thurmond Lake
- Elijah Clark State Park
Fishing spots
- Parsons Mountain Lake
- Cherokee Creek
- Lick Fork Lake
- Cliatt Creek
- J. Strom Thurmond Reservoir
- Richard B Russell Lake
Track John Grier Dam in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About John Grier Dam
Where does the data for John Grier Dam come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the Low hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of John Grier Dam.